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Ren K, Ming H, Liu S, Lang X, Jin Y, Fan J. Full-length 16S rRNA gene sequencing reveals the operating mode and chlorination-aggravated SWRO biofouling at a nuclear power plant. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2024; 90:1-17. [PMID: 39007303 DOI: 10.2166/wst.2024.185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 05/24/2024] [Indexed: 07/16/2024]
Abstract
Reverse osmosis (RO) membrane fouling and biological contamination problems faced by seawater desalination systems are microbiologically related. We used full-length 16S rRNA gene sequencing to assess the bacterial community structure and chlorine-resistant bacteria (CRB) associated with biofilm growth in different treatment processes under the winter mode of a chlorinated seawater desalination system in China. At the outset of the winter mode, certain CRB, such as Acinetobacter, Pseudomonas, and Bacillus held sway over the bacterial community structure, playing a pivotal role in biofouling. At the mode's end, Deinococcus and Paracoccus predominated, with Pseudomonas and Roseovarius following suit, while certain CRB genera still maintained their dominance. RO and chlorination are pivotal factors in shaping the bacterial community structure and diversity, and increases in total heterotrophic bacterial counts and community diversity in safety filters may adversely affect the effectiveness of subsequent RO systems. Besides, the bacterial diversity and culturable biomass in the water produced by the RO system remain high, and some conditionally pathogenic CRBs pose a certain microbial risk as a source of drinking water. Targeted removal of these CRBs will be an important area of research for advancing control over membrane clogging and ensuring water quality safety in the future.
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Affiliation(s)
- Kaijia Ren
- State Environmental Protection Key Laboratory of Coastal Ecosystem, National Marine Environmental Monitoring Center, Dalian 116021, China; These authors contributed equally to this work
| | - Hongxia Ming
- State Environmental Protection Key Laboratory of Coastal Ecosystem, National Marine Environmental Monitoring Center, Dalian 116021, China; These authors contributed equally to this work
| | - Siyu Liu
- State Environmental Protection Key Laboratory of Coastal Ecosystem, National Marine Environmental Monitoring Center, Dalian 116021, China; College of Marine Ecology and Environment, Shanghai Ocean University, Shanghai 201306, China
| | - Xianlong Lang
- State Environmental Protection Key Laboratory of Coastal Ecosystem, National Marine Environmental Monitoring Center, Dalian 116021, China; College of Marine Technology and Environment, Dalian Ocean University, Dalian 116021, China
| | - Yuan Jin
- State Environmental Protection Key Laboratory of Coastal Ecosystem, National Marine Environmental Monitoring Center, Dalian 116021, China
| | - Jingfeng Fan
- State Environmental Protection Key Laboratory of Coastal Ecosystem, National Marine Environmental Monitoring Center, Dalian 116021, China E-mail:
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Shi Q, Sun L, Gao J, Li F, Chen D, Shi T, Tan Y, Chang H, Liu X, Kang J, Lu F, Huang Z, Zhao H. Effects of sodium lauryl sulfate and postbiotic toothpaste on oral microecology. J Oral Microbiol 2024; 16:2372224. [PMID: 38939048 PMCID: PMC11210412 DOI: 10.1080/20002297.2024.2372224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Accepted: 06/18/2024] [Indexed: 06/29/2024] Open
Abstract
The diversity and delicate balance of the oral microbiome contribute to oral health, with its disruption leading to oral and systemic diseases. Toothpaste includes elements like traditional additives such as sodium lauryl sulfate (SLS) as well as novel postbiotics derived from probiotics, which are commonly employed for maintaining oral hygiene and a healthy oral cavity. However, the response of the oral microbiota to these treatments remains poorly understood. In this study, we systematically investigated the impact of SLS, and toothpaste containing postbiotics (hereafter, postbiotic toothpaste) across three systems: biofilms, animal models, and clinical populations. SLS was found to kill bacteria in both preformed biofilms (mature biofilms) and developing biofilms (immature biofilms), and disturbed the microbial community structure by increasing the number of pathogenic bacteria. SLS also destroyed periodontal tissue, promoted alveolar bone resorption, and enhanced the extent of inflammatory response level. The postbiotic toothpaste favored bacterial homeostasis and the normal development of the two types of biofilms in vitro, and attenuated periodontitis and gingivitis in vivo via modulation of oral microecology. Importantly, the postbiotic toothpaste mitigated the adverse effects of SLS when used in combination, both in vitro and in vivo. Overall, the findings of this study describe the impact of toothpaste components on oral microflora and stress the necessity for obtaining a comprehensive understanding of oral microbial ecology by considering multiple aspects.
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Affiliation(s)
- Qingying Shi
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin University of Science and Technology, Tianjin, China
| | - Lianlian Sun
- Stomatology Department, Binhai Hospital of Peking University, Tianjin, China
| | - Jing Gao
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Fengzhu Li
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Dongxiao Chen
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Tingting Shi
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Youlan Tan
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Huimin Chang
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Xiaozhi Liu
- Central Laboratory, Binhai Hospital of Peking University, Tianjin, China
| | - Jian Kang
- Periodontal Disease Department, Tianjin Stomatological Hospital, Tianjin, China
| | - Fuping Lu
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin University of Science and Technology, Tianjin, China
| | - Zhengmei Huang
- Oral and Skin Microecology Institute of Tust & Benzhen, Science and Technology Park of Tianjin University of Science and Technology, Tianjin, China
| | - Huabing Zhao
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin University of Science and Technology, Tianjin, China
- Oral and Skin Microecology Institute of Tust & Benzhen, Science and Technology Park of Tianjin University of Science and Technology, Tianjin, China
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3
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Chen C, Yang Y, Lee CH, Takizawa S, Zhang Z, Ng HY, Hou LA. Functionalization of seawater reverse osmosis membrane with quorum sensing inhibitor to regulate microbial community and mitigate membrane biofouling. WATER RESEARCH 2024; 253:121358. [PMID: 38402750 DOI: 10.1016/j.watres.2024.121358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2023] [Revised: 02/06/2024] [Accepted: 02/21/2024] [Indexed: 02/27/2024]
Abstract
Membrane biofouling is a challenge to be solved for the stable operation of the seawater reverse osmosis (SWRO) membrane. This study explored the regulation mechanism of quorum sensing (QS) inhibition on microbial community composition and population-level behaviors in seawater desalination membrane biofouling. A novel antibiofouling SWRO membrane (MA_m) by incorporating one of quorum sensing inhibitors (QSIs), methyl anthranilate (MA) was prepared. It exhibited enhanced anti-biofouling performance than the exogenous addition of QSIs, showing long-term stability and alleviating 22 % decrease in membrane flux compared with the virgin membrane. The results observed that dominant bacteria Epsilon- and Gamma-proteobacteria (Shewanella, Olleya, Colwellia, and Arcobacter), which are significantly related to (P ≤ 0.01) the metabolic products (i.e., polysaccharides, proteins and eDNA), are reduced by over 80 % on the MA_m membrane. Additionally, the introduction of MA has a more significant impact on the QS signal-sensing pathway through binding to the active site of the transmembrane sensor receptor. It effectively reduces the abundance of genes encoding QS and extracellular polymeric substance (EPS) (exopolysaccharides (i.e., galE and nagB) and amino acids (i.e., ilvE, metH, phhA, and serB)) by up to 50 % and 30 %, respectively, resulting in a reduction of EPS by more than 50 %, thereby limiting the biofilm formation on the QSI-modified membrane. This study provides novel insights into the potential of QSIs to control consortial biofilm formation in practical SWRO applications.
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Affiliation(s)
- Chao Chen
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China
| | - Yu Yang
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China.
| | - Chung-Hak Lee
- School of Chemical and Biological Engineering, Seoul National University, Seoul 08826, Republic of Korea
| | - Satoshi Takizawa
- Department of Urban Engineering, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Zhenghua Zhang
- Institute of Environmental Engineering & Nano-Technology, Tsinghua-Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, Guangdong, China
| | - How Yong Ng
- Center for Water Research, Advanced Institute of Natural Sciences, Beijing Normal University, Zhuhai 519087, China; Environmental Research Institute, National University of Singapore, 5A Engineering Drive 1, Singapore 117411, Singapore
| | - Li-An Hou
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China
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4
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Chen C, Yang Y, Graham NJD, Li Z, Yang X, Wang Z, Farhat N, Vrouwenvelder JS, Hou LA. A comprehensive evaluation of the temporal and spatial fouling characteristics of RO membranes in a full-scale seawater desalination plant. WATER RESEARCH 2024; 249:120914. [PMID: 38007899 DOI: 10.1016/j.watres.2023.120914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 11/20/2023] [Accepted: 11/22/2023] [Indexed: 11/28/2023]
Abstract
The fouling of seawater reverse osmosis (SWRO) membranes remains a persistent challenge in desalination. Previous research has focused mainly on fouling separately; however, organic, inorganic, and biofouling can coexist and influence each other. Hence, in-depth study of the spatiotemporal changes in actual combined fouling in full-scale seawater desalination will provide more effective information for fouling investigation and control. In this study, we monitored (i) the operational performance of a full-scale desalination plant for 7 years and (ii) the development and characterization of membrane and spacer fouling at different locations of spiral-wound membrane modules sampled after 2.5-, 3.5-, and 7-year operation. The findings showed that (i) operational performance indicators declined with time (normalized flux 40 % reduction, salt rejection 2 % in 7 years), with a limited effect of the 20-day cleaning frequency, (ii) fouling accumulation in the membrane module mainly occurred at the feed side of the lead module and the microbial community in these area exhibited the highest diversity, (iii) the dominant microbial OTUs belonged mainly to Proteobacteria (43-70 %), followed by Bacteroidetes (10-11 %), (iv) Phylogenetic molecular ecological networks and Spearman correlation analysis revealed that Chloroflexi (Anaerolineae) and Planctomycetes were keystone species in maintaining the community structure and biofilm maturation and significantly impacted the foulant content on the SWRO membrane, even with low abundance, and that (v) fouling accumulation was composed of polysaccharides, soluble microbial products, marine humic acid-like substances, and inorganic Ca/Fe/Mg/Si dominate the fouling layer of both the membrane and spacer. Overall, variation partitioning analysis quantitatively describes the increasing contribution of biofouling over time. Ultimately, the organic‒inorganic-biofouling interaction (70 %) significantly contributed to the overall fouling of the membrane after 7 years of operation. These results can be used to develop more targeted fouling control strategies to optimize SWRO desalination plant design and operation.
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Affiliation(s)
- Chao Chen
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China
| | - Yu Yang
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China.
| | - Nigel J D Graham
- Department of Civil and Environmental Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, UK
| | - Zhenyu Li
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Xingtao Yang
- Qingdao Bcta Desalination Co., Ltd, Qingdao, 266100, China
| | - Zhining Wang
- Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao 266237, China
| | - Nadia Farhat
- Water Desalination and Reuse Center (WDRC), Biological and Environmental Science & Engineering (BESE) Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Johannes S Vrouwenvelder
- Water Desalination and Reuse Center (WDRC), Biological and Environmental Science & Engineering (BESE) Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Li-An Hou
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China
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El-Malah SS, Rasool K, Jabbar KA, Sohail MU, Baalousha HM, Mahmoud KA. Marine Bacterial Community Structures of Selected Coastal Seawater and Sediment Sites in Qatar. Microorganisms 2023; 11:2827. [PMID: 38137970 PMCID: PMC10745943 DOI: 10.3390/microorganisms11122827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2023] [Revised: 11/09/2023] [Accepted: 11/12/2023] [Indexed: 12/24/2023] Open
Abstract
Severe environmental conditions can have a diverse impact on marine microorganisms, including bacteria. This can have an inevitable impact on the biofouling of membrane-based desalination plants. In this work, we have utilized indicator bacteria such as total coliform, fecal coliform, and Pseudomonas aeruginosa, as well as 16S rRNA sequencing, to investigate the impact of environmental conditions and spatial variations on the diversity of bacterial communities in the coastal waters and sediments from selected sites in Qatar. The concentration levels of indicator bacteria were affected by increasing temperatures and pH, and by decreasing salinity of seawater samples. Diversity indices and the molecular phylogeny demonstrated that Proteobacteria, Bacteroidetes, and Cyanobacteria were the dominant phyla in all locations. The most abundant operational taxonomic units (OTUs) at the family level were from Flavobacteriaceae (27.07%, 4.31%) and Rhodobacteraceae (22.51%, 9.86%) in seawater and sediment, respectively. Alphaproteobacteria (33.87%, 16.82%), Flavobacteria (30.68%, 5.84%), and Gammaproteobacteria (20.35%, 12.45%) were abundant at the species level in both seawater and sediment, while Clostridia (13.72%) was abundant in sediment only. The results suggest that sediment can act as a reservoir for indicator bacteria, with higher diversity and lower abundance compared to seawater.
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Affiliation(s)
- Shimaa S. El-Malah
- Qatar Environment and Energy Research Institute (QEERI), Hamad Bin Khalifa University, Qatar Foundation, Doha P.O. Box 34110, Qatar; (S.S.E.-M.); (K.R.); (K.A.J.)
| | - Kashif Rasool
- Qatar Environment and Energy Research Institute (QEERI), Hamad Bin Khalifa University, Qatar Foundation, Doha P.O. Box 34110, Qatar; (S.S.E.-M.); (K.R.); (K.A.J.)
| | - Khadeeja Abdul Jabbar
- Qatar Environment and Energy Research Institute (QEERI), Hamad Bin Khalifa University, Qatar Foundation, Doha P.O. Box 34110, Qatar; (S.S.E.-M.); (K.R.); (K.A.J.)
| | | | - Husam Musa Baalousha
- Department of Geosciences, College of Petroleum Engineering and Geosciences, King Fahd University of Petroleum and Minerals (KFUPM), Dhahran 31261, Saudi Arabia;
| | - Khaled A. Mahmoud
- Qatar Environment and Energy Research Institute (QEERI), Hamad Bin Khalifa University, Qatar Foundation, Doha P.O. Box 34110, Qatar; (S.S.E.-M.); (K.R.); (K.A.J.)
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6
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Chen X, Zhang X, Yu H, Han M, Sun J, Liu G, Ji Y, Zhai C, Zhu L, Shao H, Liang Y, McMinn A, Wang M. Spatio-temporal variation of bacterial community structure in two intertidal sediment types of Jiaozhou Bay. ENVIRONMENTAL RESEARCH 2023; 237:116743. [PMID: 37500038 DOI: 10.1016/j.envres.2023.116743] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 07/11/2023] [Accepted: 07/24/2023] [Indexed: 07/29/2023]
Abstract
The intertidal sediment environment is dynamic and the biofilm bacterial community within it must constantly adapt, but an understanding of the differences in the biofilm bacterial community within sediments of different types is still relatively limited. The semi-enclosed Jiaozhou Bay has a temperate monsoon climate, with strong currents at the mouth of the bay. In this study, the structure of the bacterial community in Jiaozhou Bay sediment biofilms are described using high-throughput 16 S rRNA gene sequencing and the effects of temporal change and different sediment environment types are discussed. Alpha diversity was significantly higher in sandy samples than in muddy samples. Sandy sediments with increased heterogeneity promote bacterial aggregation. Beta diversity analysis showed significant differences between sediment types and between stations. Proteobacteria and Acidobacteria were significantly more abundant at ZQ, while Campilobacterota was significantly more abundant at LC. The relative abundances of Bacteroidetes, Campilobacterota, Firmicutes, and Chloroflexi were significantly higher in the muddy samples, while Actinobacteria and Proteobacteria were higher in the sandy samples. There were different phylum-level biomarkers between sediment types at different stations. There were also different patterns of functional enrichment in biogeochemical cycles between sediment types and stations with the former having more gene families that differed significantly, highlighting their greater role in determining bacterial function. Bacterial amplicon sequence variant variation between months was less than KEGG ortholog variation between months, presumably the temporal change had an impact on shaping the intertidal sediment bacterial community, although this was less clear at the gene family level. Random forest prediction yielded a combination of 43 family-level features that responded well to temporal change, reflecting the influence of temporal change on sediment biofilm bacteria.
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Affiliation(s)
- Xuechao Chen
- College of Marine Life Sciences, Institute of Evolution and Marine Biodiversity, Frontiers Science Center for Deep Ocean Multispheres and Earth System, Center for Ocean Carbon Neutrality, Ocean University of China, Qingdao, 266003, China
| | - Xinran Zhang
- College of Marine Life Sciences, Institute of Evolution and Marine Biodiversity, Frontiers Science Center for Deep Ocean Multispheres and Earth System, Center for Ocean Carbon Neutrality, Ocean University of China, Qingdao, 266003, China
| | - Hao Yu
- College of Marine Life Sciences, Institute of Evolution and Marine Biodiversity, Frontiers Science Center for Deep Ocean Multispheres and Earth System, Center for Ocean Carbon Neutrality, Ocean University of China, Qingdao, 266003, China
| | - Meiaoxue Han
- College of Marine Life Sciences, Institute of Evolution and Marine Biodiversity, Frontiers Science Center for Deep Ocean Multispheres and Earth System, Center for Ocean Carbon Neutrality, Ocean University of China, Qingdao, 266003, China
| | - Jianhua Sun
- College of Marine Life Sciences, Institute of Evolution and Marine Biodiversity, Frontiers Science Center for Deep Ocean Multispheres and Earth System, Center for Ocean Carbon Neutrality, Ocean University of China, Qingdao, 266003, China
| | - Gang Liu
- College of Marine Life Sciences, Institute of Evolution and Marine Biodiversity, Frontiers Science Center for Deep Ocean Multispheres and Earth System, Center for Ocean Carbon Neutrality, Ocean University of China, Qingdao, 266003, China
| | - Yan Ji
- College of Marine Life Sciences, Institute of Evolution and Marine Biodiversity, Frontiers Science Center for Deep Ocean Multispheres and Earth System, Center for Ocean Carbon Neutrality, Ocean University of China, Qingdao, 266003, China
| | - Chuan Zhai
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS, 7001, Australia
| | - Liyan Zhu
- College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China
| | - Hongbing Shao
- College of Marine Life Sciences, Institute of Evolution and Marine Biodiversity, Frontiers Science Center for Deep Ocean Multispheres and Earth System, Center for Ocean Carbon Neutrality, Ocean University of China, Qingdao, 266003, China; UMT-OUC Joint Centre for Marine Studies, Qingdao, 266003, China
| | - Yantao Liang
- College of Marine Life Sciences, Institute of Evolution and Marine Biodiversity, Frontiers Science Center for Deep Ocean Multispheres and Earth System, Center for Ocean Carbon Neutrality, Ocean University of China, Qingdao, 266003, China; UMT-OUC Joint Centre for Marine Studies, Qingdao, 266003, China.
| | - Andrew McMinn
- College of Marine Life Sciences, Institute of Evolution and Marine Biodiversity, Frontiers Science Center for Deep Ocean Multispheres and Earth System, Center for Ocean Carbon Neutrality, Ocean University of China, Qingdao, 266003, China; Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS, 7001, Australia.
| | - Min Wang
- College of Marine Life Sciences, Institute of Evolution and Marine Biodiversity, Frontiers Science Center for Deep Ocean Multispheres and Earth System, Center for Ocean Carbon Neutrality, Ocean University of China, Qingdao, 266003, China; UMT-OUC Joint Centre for Marine Studies, Qingdao, 266003, China; Haide College, Ocean University of China, Qingdao, 266003, China; The Affiliated Hospital of Qingdao University, Qingdao, 266000, China.
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7
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Lee MH, Choi SJ, Jang D, Kang S, Jung HJ, Hwang DS. A peptide of PilZ domain-containing protein controls wastewater-treatment-membrane biofouling by inducing bacterial attachment. WATER RESEARCH 2023; 240:120085. [PMID: 37244016 DOI: 10.1016/j.watres.2023.120085] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 05/02/2023] [Accepted: 05/15/2023] [Indexed: 05/29/2023]
Abstract
Membrane-based wastewater reclamation is used to mitigate water scarcity; however, irreversible biofouling is an elusive problem that hinders the efficiency of a forward-osmosis (FO) membrane-based process, and the protein responsible for fouling is unknown. Herein, we identified fouling proteins by analyzing the microbiome and proteome of wastewater extracellular polymeric substances responsible for strong irreversible FO-membrane fouling. The IGLSSLPR peptide of a PilZ domain-containing protein was found to recruit bacterial attachment when immobilized on the membrane surface while suppressing it when dissolved, in a similar manner to the Arg-Gly-Asp (RGD) peptide in mammalian cell cultures. Bacteria adhere to IGLSSLPR and poly-l-lysine-coated membranes with similar energies and exhibit water fluxes that decline similarly, which is ascribable to interaction as strong as electrostatic interactions in the peptide-coated membranes. We conclude that IGLSSLPR is the key domain responsible for membrane fouling and can be used to develop antifouling technology against bacteria, which is similar to the current usage of RGD peptide in mammalian cell cultures.
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Affiliation(s)
- Min Hee Lee
- Division of Environmental Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Gyeongsangbuk-do, 37673, Republic of Korea
| | - Seung-Ju Choi
- Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
| | - Duksoo Jang
- Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea; Department of Global Smart City, Sungkyunkwan University (SKKU), 2066 Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do, 16419, Republic of Korea
| | - Seoktae Kang
- Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea.
| | - Hee-Jung Jung
- Division of Environmental Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Gyeongsangbuk-do, 37673, Republic of Korea; R&D Center, ANPOLY INC., Pohang, Gyeongsangbuk-do, 37666, Republic of Korea.
| | - Dong Soo Hwang
- Division of Environmental Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Gyeongsangbuk-do, 37673, Republic of Korea; Institute for Convergence Research and Education in Advanced Technology, Yonsei University International Campus I-CREATE, Incheon 21983, South Korea.
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8
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Ran N, Sorek G, Stein N, Sharon-Gojman R, Herzberg M, Gillor O. Multispecies biofilms on reverse osmosis membrane dictate the function and characteristics of the bacterial communities rather than their structure. ENVIRONMENTAL RESEARCH 2023; 231:115999. [PMID: 37105294 DOI: 10.1016/j.envres.2023.115999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 04/07/2023] [Accepted: 04/25/2023] [Indexed: 05/12/2023]
Abstract
The main reason for the deterioration of membrane operation during water purification processes is biofouling, which has therefore been extensively studied. Biofouling was shown to reduce membrane performance reflected by permeate flux decline, reduced selectivity, membrane biodegradation, and consequently, an increase in energy consumption. Studies of biofouling focused on the identification of the assembled microbial communities, the excretion of extracellular polymeric substances (EPS), and their combined role in reduced membrane performance and lifetime. However, the link between the structure and function of biofouling communities has not been elucidated to date. Here, we provide a novel insight, suggesting that bacterial functions rather than composition control biofouling traits on reverse osmosis (RO) membranes. We studied the potential activity of RO biofilms at metatranscriptome resolution, accompanied by the morphology and function of the biofouling layer over time, including microscopy and EPS composition, adhesion, and viscoelastic properties. To that end, we cultivated natural multispecies biofilms in RO membranes under treated wastewater flow and extracted RNA to study their taxonomies and gene expression profiles. Concomitantly, the biofilm structure was visualized using both scanning electron microscopy and laser scanning confocal microscopy. We also used quartz crystal microbalance with dissipation to characterize the affinity of EPS to membrane-mimetic sensors and evaluated the viscoelasticity of the Ex-Situ EPS layer formed on the sensor. Our results showed that different active bacterial taxa across five taxonomic classes were assembled on the RO membrane, while the composition shifted between 48 and 96 h. However, regardless of the composition, the maturation of the biofilm resulted in the expression of similar gene families tightly associated with the temporal kinetics of the EPS composition, adhesion, and viscoelasticity. Our findings highlight the temporal selection of specific microbial functions rather than composition, featuring the adhesion kinetics and viscoelastic properties of the RO biofilm.
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Affiliation(s)
- Noya Ran
- Zuckerberg Institute for Water Research, Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben Gurion, 84990, Israel
| | - Gil Sorek
- Department of Life Science, Ben-Gurion University of the Negev, Be'er-Sheva, 84105, Israel; National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Be'er-Sheva, 84105, Israel
| | - Noa Stein
- Zuckerberg Institute for Water Research, Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben Gurion, 84990, Israel
| | - Revital Sharon-Gojman
- Zuckerberg Institute for Water Research, Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben Gurion, 84990, Israel
| | - Moshe Herzberg
- Zuckerberg Institute for Water Research, Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben Gurion, 84990, Israel.
| | - Osnat Gillor
- Zuckerberg Institute for Water Research, Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben Gurion, 84990, Israel.
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9
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Biofouling in Membrane Bioreactors: Mechanism, Interactions and Possible Mitigation Using Biosurfactants. Appl Biochem Biotechnol 2023; 195:2114-2133. [PMID: 36385366 DOI: 10.1007/s12010-022-04261-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/08/2022] [Indexed: 11/18/2022]
Abstract
Biofouling roots damage to membrane bioreactors (MBRs), such as physical, functional and organisational changes and even therefore clogging of the membrane pores and successive microbial degradation. Further, it blocks the pores, results into a biomass cake and in due course reduces the membrane flux and leads to an increase in the operational costs. MBR fouling contributed to the rise in transmembrane pressure (TMP) and decrease in permeate flux (in case of constant pressure operation mode). Chemical surfactants adopted for the cleaning of membrane surfaces have certain disadvantages such as toxicity manifestations, damage to the membranes and high CMC concentrations. Biosurfactant surfactants have attained increasing interest due to their low toxicity, biodegradability, stability to extreme environmental conditions such as temperatures, pH and tolerance to salinity. The biosurfactants trapped the foulants via micelle formation, which distresses hydrophobic interactions amongst bacteria and the surface. Rhamnolipids as an anionic biosurfactant pose a significant interfacial potential and have affinity to bind organic matter. The present review discusses the problem of biofouling in MBRs, type and interactions of foulants involved and also highlights the mechanisms of biosurfactant cleaning, effect of different parameters, effect of concentration, TMP, flux recovery, permeability, mitigation practices and challenges.
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10
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Cabrera J, Guo HY, Yao JL, Wang XM. The effect of different carbon sources on biofouling in membrane fouling simulators: microbial community and implications. BIOFOULING 2022; 38:747-763. [PMID: 36224109 DOI: 10.1080/08927014.2022.2129017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 09/01/2022] [Accepted: 09/13/2022] [Indexed: 06/16/2023]
Abstract
Biofouling is a problem affecting the operation of nanofiltration systems due to the complexity of the carbon matrix affecting bacteria and biofilm growth. This study used membrane fouling simulators to investigate the effects of five different carbon sources on the biofouling of nanofiltration membranes. For all the carbon sources analyzed, the increase in pressure drop was most accelerated for acetate. The use of acetate as the single carbon source produced less adenosine triphosphate but more extracellular polymers than glucose. The microbial community was analyzed using 16 s rRNA. The use of more than a single carbon source produced an increase in bacteria diversity even at similar concentrations. The relative abundance of proteobacteria was the highest at the phylum level (95%) when a single carbon source was added. Additionally, it was found that the use of different carbon sources produced a shift in the microbial community, affecting the biofouling and pressure drop on membranes.
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Affiliation(s)
- Johny Cabrera
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, China
| | - Hao-Yu Guo
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, China
| | | | - Xiao-Mao Wang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, China
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11
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Aydin S, Can K, Çalışkan M, Balcazar JL. Bacteriophage cocktail as a promising bio-enhancer for methanogenic activities in anaerobic membrane bioreactors. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 832:154716. [PMID: 35337865 DOI: 10.1016/j.scitotenv.2022.154716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Revised: 03/16/2022] [Accepted: 03/17/2022] [Indexed: 06/14/2023]
Abstract
This study aimed to explore the effect of a bacteriophage cocktail, pyophage, on the treatment of wastewater containing antibiotics in an anaerobic membrane bioreactor (AnMBR). During the operational period, performance of the AnMBR was monitored through the changes in chemical oxygen demand (COD), antibiotic removal, transmembrane pressure, and biogas production. Microbial community structure and composition, as well as the occurrence of antibiotic resistance genes were analyzed through shotgun metagenomics analysis. When exposed to pyophage, COD removal efficiency was enhanced up to 96%, whereas membrane fouling was delayed by 25%. Average biogas production was doubled from 224.2 mL/d in control with antibiotics to 447.3 mL/d when exposed to pyophage cocktail with considerable alterations to the archaeal and bacterial community structures. Most notably, the methanogenic community shifted from dominance of Methanothermobacter to Methanoculleus, along with syntrophic bacteria. The results provide insight into the synergistic effects of phage-bacteria and methanogenic communities and illustrate the potential of bacteriophages as bio-enhancers.
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Affiliation(s)
- Sevcan Aydin
- Division of Biotechnology, Biology Department, Faculty of Science, Istanbul University, Vezneciler, 34134 Istanbul, Turkey.
| | - Kubra Can
- Department of Medical Microbiology, Istanbul University-Cerrahpasa, Cerrahpaşa, 34320 Istanbul, Turkey
| | - Mahmut Çalışkan
- Division of Biotechnology, Biology Department, Faculty of Science, Istanbul University, Vezneciler, 34134 Istanbul, Turkey
| | - Jose L Balcazar
- Catalan Institute for Water Research (ICRA), 17003 Girona, Spain; University of Girona, 17004 Girona, Spain
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12
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Luo X, Yang Y, Xie S, Wang W, Li N, Wen C, Zhu S, Chen L. Drying and rewetting induce changes in biofilm characteristics and the subsequent release of metal ions. JOURNAL OF HAZARDOUS MATERIALS 2022; 433:128832. [PMID: 35390615 DOI: 10.1016/j.jhazmat.2022.128832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 03/15/2022] [Accepted: 03/30/2022] [Indexed: 06/14/2023]
Abstract
Drying and rewetting can markedly influence the microbial structure and function of river biofilm communities and potentially result in the release of metal ions from biofilms containing metals. However, little information is available on the response of metal-enriched biofilms to drying and rewetting over time. In this study, natural biofilms were allowed to develop in four rotating annular bioreactors for 2-11 weeks, followed by drying for 5 days and rewetting for another 5 days. Subsequently, we assessed Zn, Cd, and As desorption from the biofilms and other related parameters (microbial community structure, biofilm morphology, enzyme activity, and surface components as well as characteristics). High-throughput sequencing of the 16 S rRNA gene and confocal laser scanning microscopy revealed that the biofilm architecture and bacterial communities were distinct in different growth phases and under drying and rewetting conditions (permutational multivariate analysis of variance; p = 0.001). Proteobacteria was the dominant bacterial phylum, accounting for 69.7-90.1% of the total content. Kinetic experiments revealed that the drying and rewetting process increased metal desorption from the biofilm matrix. The desorption of heavy metals was affected by the age of the biofilm, with the maximum amount of metal ions released from 2-week-old biofilms (one-way ANOVA, Zn: p < 0.001; Cd: p = 0.008; As: p < 0.001). The modifications in biofilm properties and decreased diversity of the bacterial community (paired t-test, p < 0.05) after drying and rewetting decreased the number of specific binding sites for metal ions. In addition, negatively charged arsenate and other anions in the liquid phase could compete with As ions for adsorption sites to promote the release of As(V) and/or reductive desorption of As(III). The results of this study and their interpretation are expected to help refine the behaviors of heavy metals in the aquatic environment.
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Affiliation(s)
- Xia Luo
- Institute of International Rivers and Eco-Security, Yunnan University, Kunming 650500, China; Yunnan Key Laboratory of International Rivers and Transboundary Eco-Security, Kunming 650500, China.
| | - Yuanhao Yang
- Institute of International Rivers and Eco-Security, Yunnan University, Kunming 650500, China; Yunnan Key Laboratory of International Rivers and Transboundary Eco-Security, Kunming 650500, China
| | - Shanshan Xie
- Institute of International Rivers and Eco-Security, Yunnan University, Kunming 650500, China; Yunnan Key Laboratory of International Rivers and Transboundary Eco-Security, Kunming 650500, China
| | - Wenwen Wang
- Institute of International Rivers and Eco-Security, Yunnan University, Kunming 650500, China; Yunnan Key Laboratory of International Rivers and Transboundary Eco-Security, Kunming 650500, China
| | - Nihong Li
- Institute of International Rivers and Eco-Security, Yunnan University, Kunming 650500, China; Yunnan Key Laboratory of International Rivers and Transboundary Eco-Security, Kunming 650500, China
| | - Chen Wen
- Institute of International Rivers and Eco-Security, Yunnan University, Kunming 650500, China; Yunnan Key Laboratory of International Rivers and Transboundary Eco-Security, Kunming 650500, China
| | - Shijun Zhu
- Institute of International Rivers and Eco-Security, Yunnan University, Kunming 650500, China; Yunnan Key Laboratory of International Rivers and Transboundary Eco-Security, Kunming 650500, China
| | - Liqiang Chen
- Institute of International Rivers and Eco-Security, Yunnan University, Kunming 650500, China; Yunnan Key Laboratory of International Rivers and Transboundary Eco-Security, Kunming 650500, China.
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Can Aggregate-Associated Organisms Influence the Fouling in a SWRO Desalination Plant? Microorganisms 2022; 10:microorganisms10040682. [PMID: 35456734 PMCID: PMC9032733 DOI: 10.3390/microorganisms10040682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 03/17/2022] [Accepted: 03/17/2022] [Indexed: 12/10/2022] Open
Abstract
This pilot study investigates the formation of aggregates within a desalination plant, before and after pre-treatment, as well as their potential impact on fouling. The objective is to provide an understanding of the biofouling potential of the feed water within a seawater reverse osmosis (SWRO) desalination plant, due to the limited removal of fouling precursors. The 16S and 18S rRNA was extracted from the water samples, and the aggregates and sequenced. Pre-treatment systems, within the plant remove < 5 µm precursors and organisms; however, smaller size particles progress through the plant, allowing for the formation of aggregates. These become hot spots for microbes, due to their nutrient gradients, facilitating the formation of niche environments, supporting the proliferation of those organisms. Aggregate-associated organisms are consistent with those identified on fouled SWRO membranes. This study examines, for the first time, the factors supporting the formation of aggregates within a desalination system, as well as their microbial communities and biofouling potential.
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14
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Xiong X, Siddique MS, Graham NJD, Yu W. Towards microplastics contribution for membrane biofouling and disinfection by-products precursors: The effect on microbes. JOURNAL OF HAZARDOUS MATERIALS 2022; 426:127797. [PMID: 34815124 DOI: 10.1016/j.jhazmat.2021.127797] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 11/06/2021] [Accepted: 11/11/2021] [Indexed: 06/13/2023]
Abstract
Public awareness of plastic pollution and its impact on the ecosystem has increased rapidly. The microplastics in raw waters and their removal during drinking water treatment is receiving growing attention, but the impact on the efficiency of ultrafiltration has not been examined previously, especially in regard to the formation potential of disinfection by-products (DBPs-FP) in effluent water. In this study, two bench-scale continuous-flow ultrafiltration systems, with and without microplastics, were operated to examine the effect of microplastics on ultrafiltration. Results showed that the microplastics not only increased microbial growth, but also affected the microbial community (e.g. families Xanthobacteraceae, Sphingomonadaceae, Leptolyngbyaceae), which can promote the production of extracellular polymeric substances and nitrogen fixation, causing rapid membrane fouling. The formation potential of THM (TCM and BDCM) and N-DBP (TCNM) species in UF permeate increased with the presence of microplastics, due to changes in water quality. Statistical analysis indicated that tyrosine-like components (C3), ammonium (NH4+-N) and tryptophan-like component (C1) can be used as indicators of the DBPs-FP. This study provides new insights into the relationship between microplastics, membrane biofouling and DBPs-FP, and the potential adverse impact of microplastics on drinking water treatment.
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Affiliation(s)
- Xuejun Xiong
- Key laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100086, China
| | - Muhammad Saboor Siddique
- Key laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100086, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Nigel J D Graham
- Department of Civil and Environmental Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, UK
| | - Wenzheng Yu
- Key laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100086, China.
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15
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Fakhri H, Arabacı DN, Ünlü İD, Yangin-Gomec C, Ovez S, Aydin S. Addition of Trichocladium canadense to an anaerobic membrane bioreactor: evaluation of the microbial composition and reactor performance. BIOFOULING 2021; 37:711-723. [PMID: 34378470 DOI: 10.1080/08927014.2021.1949002] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Revised: 06/13/2021] [Accepted: 06/22/2021] [Indexed: 06/13/2023]
Abstract
Membrane bioreactors are powerful systems for wastewater treatment and the removal of toxic compounds. However, membrane biofouling stands in the way of their widespread usage. In this study, the saprophytic fungus Trichocladium canadense was used as the bioaugmentor in an anaerobic membrane bioreactor (AnMBR) and its impact on membrane biofouling, biogas production, the microbial communities of the reactor and removal of the common antibiotics erythromycin (ERY), sulfamethoxazole (SMX) and tetracycline (TET) from synthetic wastewater was investigated. The results indicated that through bioaugmentation with 20% T. canadense, membrane biofouling was slowed by 25%, the chemical oxygen demand removal increased by 16% and a higher efficiency removal of ERY and SMX was achieved. The presence of T. canadense significantly increased the abundance and diversity of the biofilm archaeal community and the bacterial phylum Firmicutes, a known bio-foulant.
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Affiliation(s)
- Hadi Fakhri
- Department of Environmental Engineering, Istanbul Technical University, Maslak, Istanbul, Turkey
| | - Duygu Nur Arabacı
- Department of Genetics and Bioengineering, Nişantaşı University, Maslak, Istanbul, Turkey
| | - İlayda Dilara Ünlü
- Department of Bioengineering, Yildiz Technical University, Esenler, Istanbul, Turkey
| | - Cigdem Yangin-Gomec
- Department of Environmental Engineering, Istanbul Technical University, Maslak, Istanbul, Turkey
| | - Suleyman Ovez
- Department of Environmental Engineering, Istanbul Technical University, Maslak, Istanbul, Turkey
| | - Sevcan Aydin
- Division of Biotechnology, Biology Department, Faculty of Science, Istanbul University, Vezneciler, Istanbul, Turkey
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16
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Metagenomic Study of the Community Structure and Functional Potentials in Maize Rhizosphere Microbiome: Elucidation of Mechanisms behind the Improvement in Plants under Normal and Stress Conditions. SUSTAINABILITY 2021. [DOI: 10.3390/su13148079] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The community of microbes in the rhizosphere region is diverse and contributes significantly to plant growth and crop production. Being an important staple and economic crop, the maize rhizosphere microbiota has been studied in the past using culture-dependent techniques. However, these limited culturing methods often do not help in understanding the complex community of microbes in the rhizosphere. Moreover, the vital biogeochemical processes carried out by these organisms are yet to be fully characterized. Herein, shotgun metagenomics, which enables the holistic study of several microbial environments, was employed to examine the community structure and functional potentials of microbes in the maize rhizosphere and to assess the influence of environmental variables on these. The dominant microbial phyla found in the soil environments include Actinobacteria, Microsporidia, Bacteroidetes, Thaumarchaeota, Proteobacteria and Firmicutes. Carbohydrate metabolism, protein metabolism and stress metabolism constitute the major functional categories in the environments. The beta diversity analysis indicated significant differences (p = 0.01) in the community structure and functional categories across the samples. A correlation was seen between the physical and chemical properties of the soil, and the structural and functional diversities. The canonical correspondence analysis carried out showed that phosphorus, N-NO3, potassium and organic matter were the soil properties that best influenced the structural and functional diversities of the soil microbes. It can be inferred from this study that the maize rhizosphere is a hotspot for microorganisms of agricultural and biotechnological importance which can be used as bioinoculants for sustainable agriculture.
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17
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Rehman ZU, Vrouwenvelder JS, Saikaly PE. Physicochemical Properties of Extracellular Polymeric Substances Produced by Three Bacterial Isolates From Biofouled Reverse Osmosis Membranes. Front Microbiol 2021; 12:668761. [PMID: 34349735 PMCID: PMC8328090 DOI: 10.3389/fmicb.2021.668761] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 06/07/2021] [Indexed: 11/13/2022] Open
Abstract
This work describes the chemical composition of extracellular polymeric substances (EPS) produced by three bacteria (RO1, RO2, and RO3) isolated from a biofouled reverse osmosis (RO) membrane. We isolated pure cultures of three bacterial strains from a 7-year-old biofouled RO module that was used in a full-scale seawater treatment plant. All the bacterial strains showed similar growth rates, biofilm formation, and produced similar quantities of proteins and polysaccharides. The gel permeation chromatography showed that the EPS produced by all the strains has a high molecular weight; however, the EPS produced by strains RO1 and RO3 showed the highest molecular weight. Fourier Transform Infrared Spectroscopy (FTIR), Proton Nuclear Magnetic Resonance (1H NMR), and Carbon NMR (13C NMR) were used for a detailed characterization of the EPS. These physicochemical analyses allowed us to identify features of EPS that are important for biofilm formation. FTIR analysis indicated the presence of α-1,4 glycosidic linkages (920 cm-1) and amide II (1,550 cm-1) in the EPS, the presence of which has been correlated with the fouling potential of bacteria. The presence of α-glycoside linkages was further confirmed by 13C NMR analysis. The 13C NMR analysis also showed that the EPS produced by these bacteria is chemically similar to foulants obtained from biofouled RO membranes in previous studies. Therefore, our results support the hypothesis that the majority of substances that cause fouling on RO membranes originate from bacteria. Investigation using 1H NMR showed that the EPS contained a high abundance of hydrophobic compounds, and these compounds can lead to flux decline in the membrane processes. Genome sequencing of the isolates showed that they represent novel species of bacteria belonging to the genus Bacillus. Examination of genomes showed that these bacteria carry carbohydrates-active enzymes that play a role in the production of polysaccharides. Further genomic studies allowed us to identify proteins involved in the biosynthesis of EPS and flagella involved in biofilm formation. These analyses provide a glimpse into the physicochemical properties of EPS found on the RO membrane. This knowledge can be useful in the rational design of biofilm control treatments for the RO membrane.
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Affiliation(s)
- Zahid Ur Rehman
- Water Desalination and Reuse Center, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Johannes S Vrouwenvelder
- Water Desalination and Reuse Center, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Pascal E Saikaly
- Water Desalination and Reuse Center, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
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18
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Gonzalez-Gil G, Behzad AR, Farinha ASF, Zhao C, Bucs SS, Nada T, Das R, Altmann T, Buijs PJ, Vrouwenvelder JS. Clinical Autopsy of a Reverse Osmosis Membrane Module. FRONTIERS IN CHEMICAL ENGINEERING 2021. [DOI: 10.3389/fceng.2021.683379] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The desalination of seawater using reverse osmosis membranes is an attractive solution to global freshwater scarcity. However, membrane performance is reduced by (bio)fouling. Membrane autopsies are essential for identifying the type of fouling material, and applying corrective measures to minimize membrane fouling. Information from full-scale membrane autopsies guiding improved plant operations is scant in the formal literature. In this case-study, a reverse osmosis membrane from a full-scale seawater desalination plant with a feed channel pressure drop increase of about 218% over the pressure vessel was autopsied. The simultaneous determination of microbial cells, ATP, and total organic carbon (TOC) abundances per membrane area allowed estimating the contributions of biofouling and organic fouling. The abundance of microbial cells determined by flow cytometry (up to 7 × 108 cells/cm2), and ATP (up to 21,000 pg/cm2) as well as TOC (up to 98 μg/cm2) were homogeneously distributed on the membrane. Inorganic fouling was also measured, and followed a similar coverage distribution to that of biofouling. Iron (∼150 μg/cm2, estimated by ICP-MS) was the main inorganic foulant. ATR-FTIR spectra supported that membrane fouling was both organic/biological and inorganic. High-resolution SEM-EDS imaging of cross-sectioned membranes allowed assessing the thickness of the fouling layer (up to 20 μm) and its elemental composition. Imaging results further supported the results of homogeneous fouling coverage. Moreover, imaging revealed both zones with and without compression of the polysulfone membrane layer, suggesting that the stress due to operating pressure was heterogeneous. The procedure for this membrane autopsy provided a reasonable overview of the diverse contributors of fouling and might be a starting point to building a consensus autopsy protocol. Next, it would be valuable to build a RO membrane autopsy database, which can be used as a guidance and diagnostic tool to improve the management and operation of RO desalination plants.
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Zan F, Guo G, Zheng T, Chen G. Biofilm development in a pilot-scale gravity sewer: Physical characteristics, microstructure, and microbial communities. ENVIRONMENTAL RESEARCH 2021; 195:110838. [PMID: 33581085 DOI: 10.1016/j.envres.2021.110838] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 01/30/2021] [Accepted: 01/31/2021] [Indexed: 06/12/2023]
Abstract
The existence of abundant biofilms on sewer pipeline walls can lead to negative environmental impacts, such as poisonous gas release and pipe corrosions through transforming various pollutants. Investigating the formation process of sewer biofilms is of importance in advancing knowledge of sewer operation and maintenance. In this study, the changes in physical characteristics, microstructure, and microbial communities of sewer biofilm were analyzed in-depth in a pilot-scale gravity sewer during a 45-day operation. The results show that a high specific surface area at the early stage could channel the substrates for stimulating the primary colonizers (e.g., Cytophagia, Sphingobacteriia, Alpha-, and Betaproteobacteria), which could excrete an extracellular matrix to facilitate biofilm growth. The sewer biofilms were gradually formed with 62 g VS/m2 organic content, 1.2 mm biofilm thickness, and 89 mg/cm3 dry density after 45 days operation. Moreover, the biofilm growth promoted the emergence of facultative bacteria and anaerobes (affiliated with Flavobacteriia, Gemmatimonadetes, Deltaproteobacteria, and Epsilonproteobacteria). Microelectrode analysis further verified that an anaerobic zone existed in mature biofilm with a negative oxidation-reduction potential (-105 mV), where approximately 0.1 μmol/L of sulfide was produced. Our results suggest that the migration of the microbial community correlated with the changes in the evolved physical characteristics and microstructure of sewer biofilm, and this can contribute to the strategies for sulfide control for improving sewer maintenance.
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Affiliation(s)
- Feixiang Zan
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan, China; Department of Civil and Environmental Engineering, Water Technology Center, Hong Kong Branch of Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, The Hong Kong University of Science & Technology, Clear Water Bay, Hong Kong
| | - Gang Guo
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan, China.
| | - Tianlong Zheng
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China
| | - Guanghao Chen
- Department of Civil and Environmental Engineering, Water Technology Center, Hong Kong Branch of Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, The Hong Kong University of Science & Technology, Clear Water Bay, Hong Kong.
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20
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Bai S, Huang B, Fu S, Zhu M, Hu L, Zhu L, Chen M, Zhang Z, Tan J, Zhang J, Chen H. Changes in the Distribution of Intrauterine Microbiota May Attribute to Immune Imbalance in the CBA/J×DBA/2 Abortion-Prone Mice Model. Front Immunol 2021; 12:641281. [PMID: 33763083 PMCID: PMC7982683 DOI: 10.3389/fimmu.2021.641281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 02/16/2021] [Indexed: 11/13/2022] Open
Abstract
Background: Female Genital Tract (FGT) is an important micro-ecological area of human body. Microbiota in the lower reproductive tract may subsequently invade the uterine cavity during embryo implantation and produce immune responses. CBA/J×DBA/2 mating combination has been widely used as an abortion-prone mice model but whether microbiota existed in their uterine cavity remains unclear. In this context, the role of the microbial communities in immune response deserves attention. Objective: To investigate the relationship between the distribution of microbiota in the uterine cavity of CBA/J×DBA/2 abortion-prone mouse model and the immune imbalance of the maternal-fetal interface. Methods: In this study, female CBA/J mice were paired with male DBA/2 mice to develop an abortion-prone model (BA group), and with male BALB/c mice to build a standard pregnancy model (BC group). The non-pregnant female mice were served as the control group (C group). Uterine flushing fluid and sera were collected on day 13.5 of pregnancy. 16S rRNA sequencing technology was used to analyze the distribution of intrauterine microbiota. Phylogenetic Investigation of Communities were conducted to predict the microbiota functions by Reconstruction of Unobserved States (PICRUST) and Kyoto Encyclopedia of Genes and Genomes (KEGG). The serum IL 10, INF-γ, and TNF-α levels were examined using Enzyme-linked immunosorbent assay (ELISA) method. Results: All samples were detected with microbial communities. The α diversity (p = 0.00077) had significant differences among three groups. Proteobacteria was the most dominant phylum in C group (mean = 83.21%) and BA group (mean = 43.23%). Firmicutes was dominant in BC group (mean = 46.4%), as well as the second dominant one in C group (mean = 12.63%) and BA group (mean = 40.55%). Microbiota functions were associated with metabolism and immune response through the NOD-like receptor signaling pathway. The serum IL 10 level in BA group were significantly lower than that in BC group (10.14 ± 1.90 pg/ml, n = 8; vs. 19.03 ± 1.82 pg/ml, n = 10; p = 0.004). The serum TNF-α and INF-γ level in BA group were also significantly higher than that in BC group (523.1 ± 58.14 pg/ml, n = 8 vs. 310.3 ± 28.51 pg/ml, n = 10, p = 0.0029; 69.22 ± 5.38 pg/ml, n = 8 vs. 50.85 ± 2.45 pg/ml, n = 10, p = 0.0042). Conclusion: Microbial communities were colonized in uterine cavity of CBA/J mice both at non-pregnant stage and pregnant stage when mated with both BALB/c and DBA/2 male mice. The differentially abundant microbiome may be attributed to the immune tolerance through binding to the NOD-like receptor.
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Affiliation(s)
- Shiyu Bai
- Department of Obstetrics and Gynecology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China.,Center for Reproductive Genetics and Reproductive Medicine, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Bingqian Huang
- Department of Obstetrics and Gynecology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China.,Center for Reproductive Genetics and Reproductive Medicine, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Shuai Fu
- Department of Obstetrics and Gynecology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China.,Center for Reproductive Genetics and Reproductive Medicine, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Menglan Zhu
- Department of Obstetrics and Gynecology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China.,Center for Reproductive Genetics and Reproductive Medicine, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Lihao Hu
- Department of Obstetrics and Gynecology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China.,Center for Reproductive Genetics and Reproductive Medicine, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Liqiong Zhu
- Department of Obstetrics and Gynecology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China.,Center for Reproductive Genetics and Reproductive Medicine, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Manqi Chen
- Department of Obstetrics and Gynecology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China.,Center for Reproductive Genetics and Reproductive Medicine, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Zicheng Zhang
- Department of Radiation Oncology, Shenzhen Traditional Chinese Medicine Hospital, The Fourth Clinical Medical College of Guangzhou University of Chinese Medicine, Shenzhen, China
| | - Jianping Tan
- Department of Obstetrics and Gynecology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China.,Center for Reproductive Genetics and Reproductive Medicine, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Jianping Zhang
- Department of Obstetrics and Gynecology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China.,Center for Reproductive Genetics and Reproductive Medicine, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Hui Chen
- Department of Obstetrics and Gynecology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China.,Center for Reproductive Genetics and Reproductive Medicine, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
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21
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Yanuka-Golub K, Dubinsky V, Korenblum E, Reshef L, Ofek-Lalzar M, Rishpon J, Gophna U. Anode Surface Bioaugmentation Enhances Deterministic Biofilm Assembly in Microbial Fuel Cells. mBio 2021; 12:e03629-20. [PMID: 33653887 PMCID: PMC8092319 DOI: 10.1128/mbio.03629-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2020] [Accepted: 01/19/2021] [Indexed: 11/20/2022] Open
Abstract
Microbial fuel cells (MFCs) generate energy while aiding the biodegradation of waste through the activity of an electroactive mixed biofilm. Metabolic cooperation is essential for MFCs' efficiency, especially during early colonization. Thus, examining specific ecological processes that drive the assembly of anode biofilms is highly important for shortening startup times and improving MFC performance, making this technology cost-effective and sustainable. Here, we use metagenomics to show that bioaugmentation of the anode surface with a taxonomically defined electroactive consortium, dominated by Desulfuromonas, resulted in an extremely rapid current density generation. Conversely, the untreated anode surface resulted in a highly stochastic and slower biofilm assembly. Remarkably, an efficient anode colonization process was obtained only if wastewater was added, leading to a nearly complete replacement of the bioaugmented community by Geobacter lovleyi Although different approaches to improve MFC startup have been investigated, we propose that only the combination of anode bioaugmentation with wastewater inoculation can reduce stochasticity. Such an approach provides the conditions that support the growth of specific newly arriving species that positively support the fast establishment of a highly functional anode biofilm.IMPORTANCE Mixed microbial communities play important roles in treating wastewater, in producing renewable energy, and in the bioremediation of pollutants in contaminated environments. While these processes are well known, especially the community structure and biodiversity, how to efficiently and robustly manage microbial community assembly remains unknown. Moreover, it has been shown that a high degree of temporal variation in microbial community composition and structure often occurs even under identical environmental conditions. This heterogeneity is directly related to stochastic processes involved in microbial community organization, similarly during the initial stages of biofilm formation on surfaces. In this study, we show that anode surface pretreatment alone is not sufficient for a substantial improvement in startup times in microbial fuel cells (MFCs), as previously thought. Rather, we have discovered that the combination of applying a well-known consortium directly on the anode surface together with wastewater (including the bacteria that they contain) is the optimized management scheme. This allowed a selected colonization process by the wastewater species, which improved the functionality relative to that of untreated systems.
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Affiliation(s)
- Keren Yanuka-Golub
- The Porter School of Environmental Studies, Tel Aviv University, Tel Aviv, Israel
- The Shmunis School of Biomedicine and Cancer Research, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Vadim Dubinsky
- The Shmunis School of Biomedicine and Cancer Research, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Elisa Korenblum
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Leah Reshef
- The Shmunis School of Biomedicine and Cancer Research, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | | | - Judith Rishpon
- The Porter School of Environmental Studies, Tel Aviv University, Tel Aviv, Israel
- The Shmunis School of Biomedicine and Cancer Research, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Uri Gophna
- The Porter School of Environmental Studies, Tel Aviv University, Tel Aviv, Israel
- The Shmunis School of Biomedicine and Cancer Research, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
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22
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Tian L, Wang L. Multi-omics analysis reveals structure and function of biofilm microbial communities in a pre-denitrification biofilter. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 757:143908. [PMID: 33316516 DOI: 10.1016/j.scitotenv.2020.143908] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 11/16/2020] [Accepted: 11/17/2020] [Indexed: 06/12/2023]
Abstract
The highly complex microbial communities in biofilm play crucial roles in the pollutant removal performance of wastewater treatment plants (WWTPs). In the present study, using multi-omics analysis, we studied microbial structure, key enzymes, functional traits, and key metabolic pathways of pre-denitrification biofilter in an urban WWTP in China. The analysis results of metagenomic and metaproteomic showed that Betaproteobacteria and Flavobacteriia were dominant in biofilms. The integrated metagenomic and metaproteomic data showed that the expression of nitrogen metabolism genes was high, and the high proportion of denitrification module indicating that denitrification was the main nitrogen removal pathway. The most abundant denitrifying bacterial genera were: Dechloromonas, Acidovorax, Bosea, Polaromonas, and Chryseobacterium. And microorganisms with denitrification potential may not be able to denitrify in the actual operation of the filter. The integrated analysis of metaproteomic and metabolomic showed that there was a correlation between biofilm microorganisms and metabolites. Metabolomic analysis indicated that metabolic profiles of biofilms varied with layer height. This study provides the first detailed microbial communities and metabolic profiles in a full-scale pre-denitrification biofilter and clarifies the mechanism of denitrification.
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Affiliation(s)
- Lu Tian
- College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China
| | - Lin Wang
- College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China.
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23
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Li H, Liu L, Wang Y, Cai L, He M, Wang L, Hu C, Jiao N, Zhang R. T4-like myovirus community shaped by dispersal and deterministic processes in the South China Sea. Environ Microbiol 2020; 23:1038-1052. [PMID: 33089595 PMCID: PMC7984403 DOI: 10.1111/1462-2920.15290] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 10/19/2020] [Indexed: 11/28/2022]
Abstract
As the most abundant and genetically diverse biological entities, viruses significantly influence ecological, biogeographical and evolutionary processes in the ocean. However, the biogeography of marine viruses and the drivers shaping viral community are unclear. Here, the biogeographic patterns of T4-like viruses and the relative impacts of deterministic (environmental selection) and dispersal (spatial distance) processes were investigated in the northern South China Sea. The dominant viral operational taxonomic units were affiliated with previously defined Marine, Estuary, Lake and Paddy Groups. A clear viral biogeographic pattern was observed along the environmental gradient from the estuary to open sea. Marine Groups I and IV had a wide geographical distribution, whereas Marine Groups II, III and V were abundant in lower-salinity continental or eutrophic environments. A significant distance-decay pattern was noted for the T4-like viral community, especially for those infecting cyanobacteria. Both deterministic and dispersal processes influenced viral community assembly, although environmental selection (e.g. temperature, salinity, bacterial abundance and community, etc.) had a greater impact than spatial distance. Network analysis confirmed the strong association between viral and bacterial community composition, and suggested a diverse ecological relationship (e.g. lysis, co-infection or mutualistic) between and within viruses and their potential bacterial hosts.
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Affiliation(s)
- Huifang Li
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Fujian Key Laboratory of Marine Carbon Sequestration, Xiamen University (Xiang'an), Xiamen, Fujian, China
| | - Lu Liu
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Fujian Key Laboratory of Marine Carbon Sequestration, Xiamen University (Xiang'an), Xiamen, Fujian, China
| | - Yu Wang
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Fujian Key Laboratory of Marine Carbon Sequestration, Xiamen University (Xiang'an), Xiamen, Fujian, China
| | - Lanlan Cai
- Department of Ocean Science, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Maoqiu He
- State Key Laboratory of Trophic Oceanography, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
| | - Long Wang
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Fujian Key Laboratory of Marine Carbon Sequestration, Xiamen University (Xiang'an), Xiamen, Fujian, China
| | - Chen Hu
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Fujian Key Laboratory of Marine Carbon Sequestration, Xiamen University (Xiang'an), Xiamen, Fujian, China
| | - Nianzhi Jiao
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Fujian Key Laboratory of Marine Carbon Sequestration, Xiamen University (Xiang'an), Xiamen, Fujian, China
| | - Rui Zhang
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Fujian Key Laboratory of Marine Carbon Sequestration, Xiamen University (Xiang'an), Xiamen, Fujian, China
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24
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Benladghem Z, Seddiki SML, Mahdad YM. Identification of bacterial biofilms on desalination reverse osmosis membranes from the mediterranean sea. BIOFOULING 2020; 36:1065-1073. [PMID: 33233947 DOI: 10.1080/08927014.2020.1851366] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Revised: 11/08/2020] [Accepted: 11/10/2020] [Indexed: 06/11/2023]
Abstract
Nanofiltration and reverse osmosis are two of the most effective surface water treatment processes. They provide water of high quality and eliminate a large amount of microorganisms, organic matter and micropollutants. However, the main limitation of membrane nanofiltration is fouling, which imposes an additional cost. This study focused on the search for microorganisms capable of reducing the performance of nanofilters and also to study autoaggregation and biofilms formation by bacterial strains isolated from the nanomembranes used in the seawater desalination plant of Souk Tlata (Algeria). It provides new microbiological data on the desalination of seawater in the southern Mediterranean basin. The results revealed 14 bacterial species isolated from six fouled reverse osmosis membranes; their quantities were significant with the dominance of Raoultella sp., Klebsiella sp., Staphylococcus sp., Stenotrophomonas sp., Micrococcus sp., and Escherichia coli. In addition, electron imaging of nanomembrane surfaces revealed complex structures of microorganisms forming biofilms.
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Affiliation(s)
- Zakaria Benladghem
- LAPSAB Lab: Antifungal Antibiotic, Physico-Chemical Synthesis and Biological Activity, University of Tlemcen, Tlemcen, Algeria
| | - Sidi Mohamed Lahbib Seddiki
- LAPSAB Lab: Antifungal Antibiotic, Physico-Chemical Synthesis and Biological Activity, University of Tlemcen, Tlemcen, Algeria
- Department of Biology, University Center of Naâma, Naâma, Algeria
| | - Yassine Moustafa Mahdad
- Department of Biology, University Center of Naâma, Naâma, Algeria
- PPABIONUT Lab: Physiology, Physiopathology and Biochemistry of Nutrition, University of Tlemcen, Tlemcen, Algeria
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25
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The Rhodamine Isothiocyanate Analogue as a Quorum Sensing Inhibitor Has the Potential to Control Microbially-Induced Biofouling. Mar Drugs 2020; 18:md18090484. [PMID: 32971837 PMCID: PMC7551263 DOI: 10.3390/md18090484] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 09/18/2020] [Indexed: 12/02/2022] Open
Abstract
Quorum sensing inhibitors (QSIs) have been proven to be an innovative approach to interfering with biofilm formation, since this process is regulated by QS signals. However, most studies have focused on single-species biofilm formation, whereas studies of the effects of signal interference on the development of multispecies biofilm, especially in the natural environment, are still lacking. Here we develop and evaluate the anti-biofilm capability of a new QSI (rhodamine isothiocyanate analogue, RIA) in natural seawater. During the experiment, biofilm characteristics, microbial communities/functions and network interactions were monitored at 36, 80, and 180 h, respectively. The results showed that the biomass and 3D structure of the biofilm were significantly different in the presence of the QSI. The expression of genes involved in extracellular polysaccharide synthesis was also downregulated in the QSI-treated group. Dramatic differences in microbial composition, β-diversity and functions between the RIA-treated group and the control group were also observed, especially in the early stage of biofilm development. Furthermore, co-occurrence model analysis showed that RIA reduced the complexity of the microbial network. This study demonstrates that rhodamine isothiocyanate analogue is an efficient QS inhibitor and has potential applications in controlling biofouling caused by multispecies biofilm, especially in the early stage of biofouling formation.
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26
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Morón-López J, Nieto-Reyes L, Molina S, Lezcano MÁ. Exploring microcystin-degrading bacteria thriving on recycled membranes during a cyanobacterial bloom. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 736:139672. [PMID: 32502787 DOI: 10.1016/j.scitotenv.2020.139672] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 05/22/2020] [Accepted: 05/22/2020] [Indexed: 06/11/2023]
Abstract
Microcystins (MC) are highly toxic secondary metabolites produced by cyanobacterial blooms in many freshwater ecosystems used for recreational and drinking water purposes. So far, biological processes remain to be optimized for an efficient cyanotoxin removal, and new approaches are necessary to compete with physical-chemical treatments. In previous studies we provided a new concept of membrane biofilm reactor made of recycled material, in which a single MC-degrading bacterial strain was inoculated. The present study evaluates the capacity of bacterial consortia associated with freshwater cyanobacterial blooms to form biofilms on recycled membranes and remove MC. Three different discarded reverse osmosis (RO) membranes, previously used in desalination plants after treating brackish water (BWd), seawater (SWd) and brackish water but transformed into nanofiltration (BWt-NF), were exposed to a cyanobacterial bloom in San Juan reservoir (central Spain). Results showed that the three recycled membranes developed a bacterial community with MC removal capacity. Little differences in bacterial coverage and MC removal efficiency between membranes were observed after their exposure in the reservoir. High-throughput sequencing of 16S rRNA gene analysis showed similar bacterial community composition at the phylum level but dissimilar at the order level between the three membranes. This suggests possible surface selectivity on the attached bacterial community. The mlr- candidates such as Burkholderiales and Methylophilales were highly abundant in BWt-NF and BWd, respectively, while mlr+ candidates (e.g. Sphingomonadales) were low abundant in all membranes. Analysis of mlrA and mlrB genes used as markers for MC degradation following mlr-pathway confirmed the presence of this pathway in all membranes. These results suggest the co-existence of both genotypes in membrane-attached native biofilms. Therefore, this study confirms that recycled membranes are suitable support for many MC-degrading bacteria, thus giving value to discarded membranes for eco-friendly and low-cost biological filters.
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Affiliation(s)
- Jesús Morón-López
- IMDEA Water Institute, Punto Com. n° 2, 28805 Alcalá de Henares, Madrid, Spain.; Chemical Engineering Department, University of Alcalá, Ctra. Madrid-Barcelona Km 33,600, 28871 Alcalá de Henares, Madrid, Spain..
| | - Lucía Nieto-Reyes
- IMDEA Water Institute, Punto Com. n° 2, 28805 Alcalá de Henares, Madrid, Spain
| | - Serena Molina
- IMDEA Water Institute, Punto Com. n° 2, 28805 Alcalá de Henares, Madrid, Spain..
| | - María Ángeles Lezcano
- Department of Molecular Evolution, Centro de Astrobiología (CSIC-INTA), 28850 Torrejón de Ardoz, Madrid, Spain
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27
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Characterization of the Bacterial Biofilm Communities Present in Reverse-Osmosis Water Systems for Haemodialysis. Microorganisms 2020; 8:microorganisms8091418. [PMID: 32942620 PMCID: PMC7564833 DOI: 10.3390/microorganisms8091418] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 08/14/2020] [Accepted: 08/19/2020] [Indexed: 02/03/2023] Open
Abstract
Biofilm in reverse osmosis (RO) membranes is a common problem in water treatment at haemodialysis facilities. Bacteria adhere and proliferate on RO membranes, forming biofilms, obstructing and damaging the membranes and allowing the transfer of bacteria and/or cellular components potentially harmful to the health of haemodialysis patients. Our aim was to characterize the bacterial community associated to biofilm of RO membranes and to identify potentially pathogenic bacteria present in the haemodialysis systems of two dialysis centres in Chile. The diversity of the bacterial communities present on RO membranes and potable and osmosed water samples was evaluated using Illumina sequencing. Additionally, bacteria from potable water, osmosed water and RO membrane samples were isolated, characterized and identified by Sanger’s sequencing. The molecular analyses of metagenomics showed that the phyla having a greater relative abundance in both dialysis centres were Proteobacteria and Planctomycetes. Pseudomonas, Stenotrophomonas, Agrobacterium, Pigmentiphaga, Ralstonia, Arthrobacter, Bacteroides and Staphylococcus were bacterial genera isolated from the different samples obtained at both haemodialysis centres. Pseudomonas spp. was a bacterial genus with greater frequency in all samples. Pseudomonas and Staphylococcus showed higher levels of resistance to the antibiotics tested. Results demonstrated the presence of potentially pathogenic bacteria, showing resistance to antimicrobials on RO membranes and in osmosed water in both dialysis centres studied.
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28
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Maddela NR, Meng F. Discrepant roles of a quorum quenching bacterium (Rhodococcus sp. BH4) in growing dual-species biofilms. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 713:136402. [PMID: 31955076 DOI: 10.1016/j.scitotenv.2019.136402] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 12/22/2019] [Accepted: 12/27/2019] [Indexed: 06/10/2023]
Abstract
Quorum quenching (QQ) is a promising alternative method for biofilm control. However, a largely unexplored issue is the mechanism through which QQ bacteria interact with biofilm-forming bacteria. Here, we explore inter-species interactions during biofilm development (using 96-well polystyrene plates in a static incubator) between the QQ bacterium Rhodococcus sp. BH4 and sludge bacteria. Experimental results revealed that strain BH4 provoked both competitive (76%) and cooperative (24%) interactions (P < 0.05) in dual-species biofilms after 24 h of incubation (mature biofilm), implying that signal destruction by strain BH4 was strain-dependent. Besides hike in the biofilm biomass (~21%), amount of extracellular polymeric substances (EPS) (25-30 times) and particle size (3.5 times) in the Serratia sp. JSB1 biofilm were increased by str. BH4. This suggests that strain BH4 may only have quenching effects against certain bacteria, and that such effects are overlooked at the community level. Taken together, present results imply that in a given biofilm community, not all QS-bacteria interact similarly with Rhodococcus sp. BH4, either because QS-bacteria are tolerant of strain BH4 or QS-bacteria have more than one mechanism for biofilm development. Overall, the QQ-strategy alone seems ineffective at controlling biofilm development, although it may be used in combination with other strategies.
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Affiliation(s)
- Naga Raju Maddela
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou, People's Republic of China; Instituto de Investigación, Universidad Técnica de Manabí, Portoviejo 130105, Ecuador; Facultad de Ciencias de la Salud, Universidad Técnica de Manabí, Portoviejo 130105, Ecuador; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Guangzhou, People's Republic of China
| | - Fangang Meng
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou, People's Republic of China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Guangzhou, People's Republic of China.
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29
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Tong X, Cui Y, Wang YH, Bai Y, Yu T, Zhao XH, Ikuno N, Luo HJ, Hu HY, Wu YH. Fouling properties of reverse osmosis membranes along the feed channel in an industrial-scale system for wastewater reclamation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 713:136673. [PMID: 31958736 DOI: 10.1016/j.scitotenv.2020.136673] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 01/11/2020] [Accepted: 01/11/2020] [Indexed: 06/10/2023]
Abstract
Membrane fouling is an inevitable disadvantage of the reverse osmosis (RO) process for wastewater reclamation. In order to clarify the development process of membrane fouling, all the fouled membranes along a feed channel of a two-stage industrial-scale RO system for wastewater reclamation (six elements in each stage) were autopsied and analyzed. The water flux and salt rejection efficiency of the fouled membranes at the head and tail were the lowest among 12 elements, thereby indicating more severe fouling on these membranes. In this RO system, most of the organic compounds deposited on the head elements of each stage were mainly composed of proteins, polysaccharides, and fulvic acid. The ATP concentrations of the foulants on the first and twelfth elements were much higher than those of the other elements, suggesting severe biofouling. Although microbes can cause organic fouling owing to extracellular polymeric substances production, no clear correlation was found between organic fouling and biofouling in this study. For example, the ATP concentrations on the second element and seventh element were similar (1.16 ng/cm2 and 1.26 ng/cm2, respectively), thereby suggesting a similar extent of biofouling, but organic fouling of the second element was relatively slight (DOC: 24.8 mg/m2) compared with that of the seventh element (DOC: 46.2 mg/m2). The seventh element (ATP: 1.26 ng/cm2) was more severely biofouled than the eighth element (ATP: 0.15 ng/cm2), but they suffered from the same level of organic fouling (DOC: 46.2 mg/m2 and 47.1 mg/m2, respectively). Approximately 70% of metallic elements, predominantly Fe, were deposited on the first element. Although the concentration of Fe in the feed water was much lower than those of Ca and Mg, the concentration of Fe on the first three elements was significantly higher than that of any other element, suggesting that Fe was more easily deposited on the RO membranes.
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Affiliation(s)
- Xin Tong
- Environmental Simulation and Pollution Control State Key Joint Laboratory, State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (SMARC), School of Environment, Tsinghua University, Beijing 100084, PR China
| | - Yong Cui
- Beijing Yizhuang Water Co., Ltd., Beijing 100176, PR China
| | - Yun-Hong Wang
- Environmental Simulation and Pollution Control State Key Joint Laboratory, State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (SMARC), School of Environment, Tsinghua University, Beijing 100084, PR China
| | - Yuan Bai
- Environmental Simulation and Pollution Control State Key Joint Laboratory, State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (SMARC), School of Environment, Tsinghua University, Beijing 100084, PR China
| | - Tong Yu
- Environmental Simulation and Pollution Control State Key Joint Laboratory, State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (SMARC), School of Environment, Tsinghua University, Beijing 100084, PR China
| | - Xue-Hao Zhao
- Environmental Simulation and Pollution Control State Key Joint Laboratory, State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (SMARC), School of Environment, Tsinghua University, Beijing 100084, PR China
| | - Nozomu Ikuno
- Kurita Water Industries Ltd., Nakano-ku, Tokyo 164-0001, Japan
| | - Hui-Jia Luo
- Beijing Yizhuang Water Co., Ltd., Beijing 100176, PR China
| | - Hong-Ying Hu
- Environmental Simulation and Pollution Control State Key Joint Laboratory, State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (SMARC), School of Environment, Tsinghua University, Beijing 100084, PR China; Shenzhen Environmental Science and New Energy Technology Engineering Laboratory, Tsinghua-Berkeley Shenzhen Institute, Shenzhen 518055, PR China
| | - Yin-Hu Wu
- Environmental Simulation and Pollution Control State Key Joint Laboratory, State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (SMARC), School of Environment, Tsinghua University, Beijing 100084, PR China.
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30
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Pinel ISM, Moed DH, Vrouwenvelder JS, van Loosdrecht MCM. Bacterial community dynamics and disinfection impact in cooling water systems. WATER RESEARCH 2020; 172:115505. [PMID: 31986397 DOI: 10.1016/j.watres.2020.115505] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 01/09/2020] [Accepted: 01/12/2020] [Indexed: 06/10/2023]
Abstract
Understanding the bacterial dynamics in cooling towers is imperative for the assessment of disinfection efficiency and management of microbial risks linked to aerosol formation. The objective of this study was to evaluate the impact of feed water on the cooling water bacterial microbiome and investigate the survival ability of its members when exposed to continuous chlorine disinfection. Water from an industrial cooling water system (2600 m3/h) was collected over a 5-month period at 3 locations along the feed water line and 3 locations in the cooling tower. ATP measurements suggested that the average ATP-per-cell in the cooling tower evolved independently from the average ATP-per-cell in the feed water. Flow cytometry and 16S rRNA gene amplicon sequencing were then combined to quantify the bacterial dynamics in the whole system. A mass balance based equation was established to determine net growth and net decay of the cooling tower bacterial communities in order to evaluate the impact of continuous chlorination (0.35-0.41 mg Cl2/L residual chlorine). The results indicated that cooling tower main community members were determined by the input feed water microbiome and the bacterial community structure was further shaped by varying decay rates of the microorganisms. Notably, the order Obscuribacterales showed to be growing in the cooling tower in the presence of residual chlorine up to 0.4 mg Cl2/L, with a recurrent net growth of 260 ± 95%, taking into account the impact of the concentration factor. This conclusion was only possible thanks to the systematic analysis described in this paper and generates discussion about the resistance of Obscuribacterales to residual chlorine. The described mass balance approach provides a high level of understanding on bacterial dynamics and should be considered for future characterization studies of cooling towers in which accurate investigation of microbiome changes is essential.
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Affiliation(s)
- I S M Pinel
- Department of Biotechnology, Faculty of Applied Sciences, Delft University of Technology, Van der Maasweg 9, 2629, HZ, Delft, the Netherlands.
| | - D H Moed
- Evides Industriewater, Schaardijk 150, 3063, NH, Rotterdam, the Netherlands.
| | - J S Vrouwenvelder
- Department of Biotechnology, Faculty of Applied Sciences, Delft University of Technology, Van der Maasweg 9, 2629, HZ, Delft, the Netherlands; Division of Biological and Environmental Science and Engineering (BESE), Water Desalination and Reuse Center (WDRC), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia.
| | - M C M van Loosdrecht
- Department of Biotechnology, Faculty of Applied Sciences, Delft University of Technology, Van der Maasweg 9, 2629, HZ, Delft, the Netherlands.
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31
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Luo H, Cui Y, Zhang H, Li C, Wang Z, Song P. Analyzing and verifying the association of spiral-wound reverse osmosis membrane fouling with different secondary effluents: full-scale experiments. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 711:135150. [PMID: 31818593 DOI: 10.1016/j.scitotenv.2019.135150] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 10/21/2019] [Accepted: 10/22/2019] [Indexed: 06/10/2023]
Abstract
In order to analyze and verify the association of the reverse osmosis (RO) membrane fouling with water quality in full-scale plants, two RO systems (40, 000 m3/d and 20, 000 m3/d) treating different secondary effluents were operated in parallel. The quality of secondary effluents and the performance of RO systems were monitored over 12 months. Difference in foulants distribution and fouling layer composition between the two systems were evaluated by membrane autopsy and foulants characterization. Results verified that: 1) the secondary effluent from municipal sewage caused more serious membrane fouling; 2) more foulants deposited on the surface of leading membrane both in two systems (3.11 ± 0.15 g/m2 and 2.93 ± 0.13 g/m2); 3) the microbial community on the RO membrane surface contained more colonizing bacteria in the system treating municipal sewage secondary effluent ; 4) organics in the secondary effluent facilitated biofouling while higher ion concentration restrained biofouling.
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Affiliation(s)
- Huijia Luo
- Beijing Key Laboratory for Green Catalysis and Separation, Department of Chemistry and Chemical Engineering, Beijing University of Technology, Beijing 100124, PR China; Beijing Boda Water Co., Ltd, Beijing 100176, PR China
| | - Yong Cui
- Beijing Boda Water Co., Ltd, Beijing 100176, PR China
| | - Hongyu Zhang
- Beijing Boda Water Co., Ltd, Beijing 100176, PR China
| | - Caifeng Li
- Beijing Boda Water Co., Ltd, Beijing 100176, PR China
| | - Zhan Wang
- Beijing Key Laboratory for Green Catalysis and Separation, Department of Chemistry and Chemical Engineering, Beijing University of Technology, Beijing 100124, PR China.
| | - Peng Song
- Beijing Boda Water Co., Ltd, Beijing 100176, PR China
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de Vries HJ, Stams AJM, Plugge CM. Biodiversity and ecology of microorganisms in high pressure membrane filtration systems. WATER RESEARCH 2020; 172:115511. [PMID: 31986400 DOI: 10.1016/j.watres.2020.115511] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Revised: 12/19/2019] [Accepted: 01/13/2020] [Indexed: 06/10/2023]
Abstract
High-pressure membrane filtration (reverse osmosis and nanofiltration) is used to purify different water sources, including wastewater, surface water, groundwater and seawater. A major concern in membrane filtration is the accumulation and growth of micro-organisms and their secreted polymeric substances, leading to reduced membrane performance and membrane biofouling. The fundamental understanding of membrane biofouling is limited despite years of research, as the means of microbial interactions and response to the conditions on the membrane surface are complicated. Here, we discuss studies that investigated the microbial diversity of fouled high-pressure membranes. High-throughput amplicon sequencing of the 16S rRNA gene have shown that Burkholderiales, Pseudomonadales, Rhizobiales, Sphingomonadales and Xanthomonadales frequently obtain a high relative abundance on fouled membranes. The bacterial communities present in the diverse feed water types and in pre-treatment compartments are different from the communities on the membrane, because high-pressure membrane filtration provides a selective environment for certain bacterial groups. The biofilms that form within the pre-treatment compartments do not commonly serve as an inoculum for the subsequent high-pressure membranes. Besides bacteria also fungi are detected in the water treatment compartments. In contrast to bacteria, the fungal community does not change much throughout membrane cleaning. The stable fungal diversity indicates that they are more significant in membrane biofouling than previously thought. By reviewing the biodiversity and ecology of microbes in the whole high pressure membrane filtration water chain, we have been able to identify potentials to improve biofouling control. These include modulation of hydrodynamic conditions, nutrient limitation and the combination of cleaning agents to target the entire membrane microbiome.
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Affiliation(s)
- Hendrik J de Vries
- Laboratory of Microbiology, Wageningen University & Research, Stippeneng 4, 6708, WE, Wageningen, the Netherlands; Wetsus, European Centre of Excellence for Sustainable Water Technology, Oostergoweg 9, 8911, MA, Leeuwarden, the Netherlands
| | - Alfons J M Stams
- Laboratory of Microbiology, Wageningen University & Research, Stippeneng 4, 6708, WE, Wageningen, the Netherlands
| | - Caroline M Plugge
- Laboratory of Microbiology, Wageningen University & Research, Stippeneng 4, 6708, WE, Wageningen, the Netherlands; Wetsus, European Centre of Excellence for Sustainable Water Technology, Oostergoweg 9, 8911, MA, Leeuwarden, the Netherlands.
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Turgay E, Steinum T, Colquhoun D, Karataş S. Environmental biofilm communities associated with early‐stage common dentex (Dentex dentex) culture. J Appl Microbiol 2019; 126:1032-1043. [DOI: 10.1111/jam.14205] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Revised: 01/03/2019] [Accepted: 01/14/2019] [Indexed: 11/29/2022]
Affiliation(s)
- E. Turgay
- Faculty of Aquatic Sciences Istanbul University Istanbul Turkey
| | - T.M. Steinum
- Faculty of Sciences Department of Molecular Biology and Genetics Istanbul University Istanbul Turkey
| | - D. Colquhoun
- Fish Health Research Group Norwegian Veterinary Institute Oslo Norway
| | - S. Karataş
- Faculty of Aquatic Sciences Istanbul University Istanbul Turkey
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Rehman ZU, Ali M, Iftikhar H, Leiknes TO. Genome-resolved metagenomic analysis reveals roles of microbial community members in full-scale seawater reverse osmosis plant. WATER RESEARCH 2019; 149:263-271. [PMID: 30448738 DOI: 10.1016/j.watres.2018.11.012] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 10/08/2018] [Accepted: 11/07/2018] [Indexed: 06/09/2023]
Abstract
Biofouling of Reverse Osmosis (RO) membrane is a significant issue for the water treatment industry. In this study, we apply the metagenomic shot-gun sequencing technology to characterise the composition and functional potential of the microbial community in a full-scale RO plant, at different stages of seawater treatment. We find Proteobacteria, Bacteroidetes and Planctomycetes to be the most abundant bacterial phyla. The genetic potential of the RO membrane microbial community shows the enrichment of genes involved in biofilm formation, representing the selective pressure of the biofilm formation process. We recover 31 metagenome-assembled genomes (MAGs) from intake (raw seawater), fouled RO membranes (leading and middle RO module) and brine reject water. A total of 25 MAGs are recovered from the biofilm samples (leading and middle RO modules), with 9 of them (36%) belonging to Planctomycetes. We investigate all 25 MAGs for genes (pili, flagella, quorum sensing, quorum quenching and nitrate reduction) that play an important role in biofilm formation and sustenance of cells. We show that Planctomycetes contain genes for the formation of flagella and pili, and the reduction of nitrate. Although genes for quorum sensing are not detected, quorum quenching genes are identified in the biofilm MAGs. Our results show that Planctomycetes, along with other microbes, play an important role in the formation and sustenance of biofilms on seawater RO membranes.
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Affiliation(s)
- Zahid Ur Rehman
- Water Desalination and Reuse Center (WDRC), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia.
| | - Muhammad Ali
- Water Desalination and Reuse Center (WDRC), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| | - Hina Iftikhar
- Water Desalination and Reuse Center (WDRC), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| | - TOrove Leiknes
- Water Desalination and Reuse Center (WDRC), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia.
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de Vries HJ, Beyer F, Jarzembowska M, Lipińska J, van den Brink P, Zwijnenburg A, Timmers PHA, Stams AJM, Plugge CM. Isolation and characterization of Sphingomonadaceae from fouled membranes. NPJ Biofilms Microbiomes 2019; 5:6. [PMID: 30701078 PMCID: PMC6347639 DOI: 10.1038/s41522-018-0074-1] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Accepted: 12/11/2018] [Indexed: 11/09/2022] Open
Abstract
Membrane filtration systems are widely applied for the production of clean drinking water. However, the accumulation of particles on synthetic membranes leads to fouling. Biological fouling (i.e., biofouling) of reverse osmosis and nanofiltration membranes is difficult to control by existing cleaning procedures. Improved strategies are therefore needed. The bacterial diversity on fouled membranes has been studied, especially to identify bacteria with specialized functions and to develop targeted approaches against these microbes. Previous studies have shown that Sphingomonadaceae are initial membrane colonizers that remain dominant while the biofilm develops. Here, we characterized 21 Sphingomonadaceae isolates, obtained from six different fouled membranes, to determine which physiological traits could contribute to colonization of membrane surfaces. Their growth conditions ranged from temperatures between 8 and 42 oC, salinity between 0.0 and 5.0% w/v NaCl, pH from 4 and 10, and all isolates were able to metabolize a wide range of substrates. The results presented here show that Sphingomonadaceae membrane isolates share many features that are uncommon for other members of the Sphingomonadaceae family: all membrane isolates are motile and their tolerance for different temperatures, salt concentrations, and pH is high. Although relative abundance is an indicator of fitness for a whole group, for the Sphingomonadaceae it does not reveal the specific physiological traits that are required for membrane colonization. This study, therefore, adds to more fundamental insights in membrane biofouling.
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Affiliation(s)
- Hendrik J. de Vries
- Laboratory of Microbiology, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands
- Wetsus, European Centre of Excellence for Sustainable Water Technology, Oostergoweg 9, 8911 MA Leeuwarden, The Netherlands
| | - Florian Beyer
- Laboratory of Microbiology, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands
- Wetsus, European Centre of Excellence for Sustainable Water Technology, Oostergoweg 9, 8911 MA Leeuwarden, The Netherlands
| | - Monika Jarzembowska
- Laboratory of Microbiology, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands
| | - Joanna Lipińska
- Wetsus, European Centre of Excellence for Sustainable Water Technology, Oostergoweg 9, 8911 MA Leeuwarden, The Netherlands
| | - Paula van den Brink
- Wetsus, European Centre of Excellence for Sustainable Water Technology, Oostergoweg 9, 8911 MA Leeuwarden, The Netherlands
| | - Arie Zwijnenburg
- Wetsus, European Centre of Excellence for Sustainable Water Technology, Oostergoweg 9, 8911 MA Leeuwarden, The Netherlands
| | - Peer H. A. Timmers
- Laboratory of Microbiology, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands
- Wetsus, European Centre of Excellence for Sustainable Water Technology, Oostergoweg 9, 8911 MA Leeuwarden, The Netherlands
| | - Alfons J. M. Stams
- Laboratory of Microbiology, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands
| | - Caroline M. Plugge
- Laboratory of Microbiology, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands
- Wetsus, European Centre of Excellence for Sustainable Water Technology, Oostergoweg 9, 8911 MA Leeuwarden, The Netherlands
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Nagaraj V, Skillman L, Li D, Ho G. Review - Bacteria and their extracellular polymeric substances causing biofouling on seawater reverse osmosis desalination membranes. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2018; 223:586-599. [PMID: 29975885 DOI: 10.1016/j.jenvman.2018.05.088] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Revised: 05/25/2018] [Accepted: 05/26/2018] [Indexed: 05/26/2023]
Abstract
Biofouling in seawater reverse osmosis (SWRO) membranes is a critical issue faced by the desalination industry worldwide. The major cause of biofouling is the irreversible attachment of recalcitrant biofilms formed by bacteria and their extracellular polymeric substances (EPS) on membrane surfaces. Transparent exopolymer particles (TEP) and protobiofilms are recently identified as important precursors of membrane fouling. Despite considerable amount of research on SWRO biofouling, the control of biofouling still remains a challenge. While adoption of better pretreatment methods may help in preventing membrane biofouling in new desalination setups, it is also crucial to effectively disperse old, recalcitrant biofilms and prolong membrane life in operational plants. Most current practices employ the use of broad spectrum biocides and chemicals that target bacterial cells to disperse mature biofilms, which are evidently inefficient. EPS, being known as the strongest structural framework of biofilms, it is essential to breakdown and disintegrate the EPS components for effective biofilm removal. To achieve this, it is necessary to understand the chemical composition and key elements that constitute the EPS of major biofouling bacterial groups in multi-species, mature biofilms. However, significant gaps in understanding the complexity of EPS are evident by the failure to achieve effective prevention and mitigation of fouling in most cases. Some of the reasons may be difficulty in sampling membranes from fully operational full-scale plants, poor understanding of microbial communities and their ecological shifts under dynamic operational conditions within the desalination process, selection of inappropriate model species for laboratory-scale biofouling studies, and the laborious process of extraction and purification of EPS. This article reviews the novel findings on key aspects of SWRO membrane fouling and control measures with particular emphasis on the key sugars in EPS. As a novel strategy to alleviate biofouling, future control methods may be aimed towards specifically disintegrating and breaking down these key sugars rather than using broad spectrum chemicals such as biocides that are currently used in the industry.
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Affiliation(s)
- Veena Nagaraj
- School of Engineering and Information Technology, Murdoch University, 90 South Street, Murdoch, Western Australia 6150, Australia.
| | - Lucy Skillman
- School of Engineering and Information Technology, Murdoch University, 90 South Street, Murdoch, Western Australia 6150, Australia.
| | - Dan Li
- School of Engineering and Information Technology, Murdoch University, 90 South Street, Murdoch, Western Australia 6150, Australia.
| | - Goen Ho
- School of Engineering and Information Technology, Murdoch University, 90 South Street, Murdoch, Western Australia 6150, Australia.
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